Standard ML
The original ML — a statically typed functional language influential in type theory, compilers, and programming language research.
static
compiled
since 1983
functionalimperative
Standard ML was the first language to be formally specified with a mathematical semantics. Its Hindley-Milner type inference, module system, and pattern matching influenced Haskell, OCaml, F#, Rust, and Swift. MLton produces highly optimised native code; SML/NJ provides an interactive environment. It is widely used in compilers courses and PL research.